Beamforming using a backplane and passive antenna element

Abstract

An active antenna element to transmit and/or receive RF (Radio Frequency) signals is positioned in relation to a backplane that reflects RF signals. One or more passive antenna elements can be disposed on a similar side of the backplane as the active antenna element. Settings of the one or more passive antenna elements are adjusted to produce an input/output beam pattern that varies depending on whether the at least one passive antenna element is reflective or transmissive. Based on this technique, an RF input output beam pattern of an antenna assembly including the backplane, active antenna element and passive antenna elements can be controlled for better reception and transmission of RF signals.

1. A beamforming apparatus, comprising:
 an active antenna element formed as a monopole having a primary axis for receiving and transmitting Radio Frequency (RF) signals; 
 at least two passive antenna elements each formed as a monopole having a primary axis for receiving and transmitting such that the respective primary axis of the active and passive antennas are aligned with one another to form a common antenna element plane that all antenna elements lie, wherein characteristics of at least one of the two passive antenna elements are adjusted to produce an input/output beam pattern for receiving/transmitting the RF signals; and 
 a backplane adjacent and substantially parallel to the common antenna plane for controlling a direction of the input/output beam pattern. 
 
   
   
     2. The apparatus of  claim 1 , wherein the backplane is disposed in a flip-top type earpiece. 
   
   
     3. The apparatus of  claim 1 , wherein characteristics of the at least one passive antenna are selectively adjusted to be reflective or transmissive to support RF beamforming. 
   
   
     4. The apparatus of  claim 1 , wherein the active antenna element is positioned between the two passive antenna elements. 
   
   
     5. The apparatus of  claim 1 , wherein the backplane limits RF exposure to a user. 
   
   
     6. The apparatus of  claim 1 , wherein characteristics of the two passive antenna elements are controlled to produce a narrower RF beam than otherwise possible without any passive antenna elements. 
   
   
     7. The apparatus of  claim 1 , wherein at least one passive antenna element is positioned up to 2 inches from the active antenna element. 
   
   
     8. The apparatus of  claim 1 , wherein at least one passive antenna element is positioned about a quarter-wavelength of a transmitted or received RF signal from the active antenna element. 
   
   
     9. The apparatus of  claim 1 , wherein a first passive antenna element is reflective and a second passive antenna element is reflective to produce a narrower RF beam pattern. 
   
   
     10. The apparatus of  claim 1 , wherein at least one passive antenna element is selectively controlled to adjust a narrowness of the input/output beam pattern. 
   
   
     11. The apparatus of  claim 1 , wherein at least one passive antenna element is selectively controlled to directionally steer the input/output beam pattern. 
   
   
     12. The apparatus of  claim 1 , wherein the backplane is disposed to be aligned with and parallel to the common antenna element plane, such that the antenna elements lie on one side of said backplane. 
   
   
     13. The apparatus of  claim 1 , wherein a shape of the input/output beam pattern depends on whether at least one passive antenna element is in a reflective or transmissive state. 
   
   
     14. The apparatus of  claim 1 , wherein the two passive antenna elements are each selectably transmissive or reflective. 
   
   
     15. A mobile device comprising a beamforming apparatus, the beamforming apparatus comprising:
 an active antenna element formed as a monopole having a primary axis for receiving and transmitting Radio Frequency (RF) signals; 
 at least two passive antenna elements each formed as a monopole having a primary axis for receiving and transmitting such that the respective primary axis of the active and passive antennas are aligned with one another to form a common antenna element plane that all antenna elements lie, wherein characteristics of at least one of the two passive antenna elements being adjusted to produce an input/output beam pattern for receiving/transmitting the RF signals; and 
 a backplane adjacent and substantially parallel to the common antenna plane for controlling a direction of the input/output beam pattern. 
 
   
   
     16. The mobile device of  claim 15 , wherein the backplane is disposed in a flip-top type earpiece. 
   
   
     17. The mobile device of  claim 15 , wherein characteristics of the at least one passive antenna are selectively adjusted to be reflective or transmissive to support RF beamforming. 
   
   
     18. The mobile device of  claim 15 , wherein the active antenna element is positioned between the two passive antenna elements. 
   
   
     19. The mobile device of  claim 15 , wherein the backplane limits RF exposure to a user. 
   
   
     20. The mobile device of  claim 15 , wherein characteristics of the two passive antenna elements are controlled to produce a narrower RF beam than otherwise possible without any passive antenna elements. 
   
   
     21. The mobile device of  claim 15 , wherein at least one passive antenna element is positioned up to 2 inches from the active antenna element. 
   
   
     22. The mobile device of  claim 15 , wherein at least one passive antenna element is positioned about a quarter-wavelength of a transmitted or received RF signal from the active antenna element. 
   
   
     23. The mobile device of  claim 15 , wherein a first passive antenna element is reflective and a second passive antenna element is reflective to produce a narrower RF beam pattern. 
   
   
     24. The mobile device of  claim 15 , wherein at least one passive antenna element is selectively controlled to adjust a narrowness of the input/output beam pattern. 
   
   
     25. The mobile device of  claim 15 , wherein at least one passive antenna element is selectively controlled to directionally steer the input/output beam pattern. 
   
   
     26. The mobile device of  claim 15 , wherein a shape of the input/output beam pattern depends on whether at least one passive antenna element is in a reflective or transmissive state. 
   
   
     27. The mobile device of  claim 15 , wherein the two passive antenna elements are each selectably transmissive or reflective.